This invention relates to novel compounds capable of inhibiting growth of food spoilage and food poisoning organisms which decrease the storage life of food products which normally spoil or lose flavor. In particular, this invention is related to a method of inhibiting the growth of food spoilage organisms.
Deterioration due to spoilage organisms occurs extensively in untreated foodstuffs such as bakery products, fish, meats, fruits, vegetables and dairy products. Industrial food processing plants incur losses both in the form of returned, deteriorated products and of impaired sales owing to inferior keeping quality of the products. Consumers, also, are caused direct losses by such deterioration but, in addition, they also run health risks because of the toxins formed by pathogens which may already be produced before the growth of such pathogens is observable. Heretofore, attempts have been made to prevent or inhibit the growth of food spoilage and food poisoning organisms by using packaging materials which have been treated by a variety of substances and by intensifying plant hygiene and thus reducing the amount of pathogen and food spoilage organism infection. Intensified food plant hygiene has successfully lowered the frequency of food spoilage organisms to a significant degree. It is impossible, however, in practice, to solve the problem completely by this approach, since it has not been possible to reduce to a sufficiently low level the organism infection by which food is contaminated even by such expedients as filtration of intake air and ultraviolet light treatment.
Aerobic microorganisms are deposited on the surface of foods through post-processing contamination from the air, from the hands of an operator, from equipment and utensils and other means. Typical examples are the formation of slime on the surfaces of slaughtered animal carcasses and the growth of bacterial colonies on sliced sausages.
Since post-processing microbial contamination, in most cases, remains on the surface of the food or feed, aerobic microorganisms generally can multiply only on the superficial layers of the food or feed. Accordingly, the measures aimed at fighting such microorganisms are concentrated on the superficial layer and the desired preventative effect can thereby be achieved. The procedures applied heretofore for the purpose of applying chemical or equivalent inhibitors of microorganisms growth on the superficial layer of food products have been by dipping the food in a solution of chemical preservative, spraying a chemical preservative solution onto the surface of food or feed and impregnating packaging material with a chemical preservative. A wide variety of such chemical preservatives have heretofore been used.
For instance, U.S. Pat. No. 2,711,976 suggests the use of amino acids to increase the resistance of custard foods to spoilage organisms and Staphylococcus aureus. U.S. Pat. No. 2,898,372 suggests calcium acetate propionate as a bread treating composition. U.S. Pat. No. 2,866,819 suggests the use of sorbic acid as a preservative in foods. U.S. Pat. No. 2,910,368 discloses the use of EDTA with sorbic acid to increase the shelf life of vegetables. U.S. Pat. No. 2,992,114 suggests the use of sorbic acid and a mild heat treatment for the preservation of fruits and vegetables. In a paper published in Applied Microbiology, Volume 18, pages 68-75 (July, 1969), Preonas et al reported on the use of a mixture of sorbic acid and propionic acid to retard the growth of Staphylococcus aureus on the surfaces of custard pies.
In accordance with the present invention, there is described and claimed a method of inhibiting the growth of pathogen and spoilage organisms which decrease the shelf life of foods by treating same with furanones. Furanones are frequently described in the literature as butyrolactones.